Method of installing a fixture and associated apparatus

ABSTRACT

A method of installing a fixture or bracket in a fuselage structure of an aircraft or spacecraft. The method includes arranging an apparatus in, on or adjacent the structure, pre-treating a surface region of the structure by heat ablation using the apparatus and forming the fixture in situ on the structure at the pre-treated surface region using the apparatus based on a digital model of the fixture. The fixture is installed by connecting the fixture to the structure at the pre-treated surface region as the fixture is formed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application EP 16157120.3 filed Feb. 24, 2016, the entire disclosure of which isincorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a method of installing a fixture, suchas a bracket, on a body structure of a vehicle, particularly a body orfuselage structure of an aircraft or spacecraft, for mounting orattaching one or more items or systems with respect to that structure.The disclosure herein also relates to an apparatus for installing afixture, such as a bracket, in or on a structure of an aircraft orspacecraft. It will be noted that the term “spacecraft” as used hereinincludes satellites and space station modules, as well as rockets androcket modules, spaceships, or parts thereof.

BACKGROUND

The installation of items and/or systems, such as electrical systemswith conduits and cables, in nautical, aeronautical or automotiveapplications typically involves the use of mounting fixtures or bracketswhich need to be secured to a structure (e.g., vehicle chassis or hullstructure) for then supporting those systems. Conventionally, thesefixtures are secured to the structure via fasteners, such as rivets,clips or screws, or via an adhesive.

Some disadvantages of mechanical fasteners, like rivets and screws,include that the fixture or bracket requires bores for the fasteners,that the fixture needs to be positioned with respect to the bores, andthat it requires a fastening operation to then secure the fasteners.Depending on the particular application, the fixture or bracket may alsothen need to be sealed around the fasteners and bores. These stepsnaturally involve process costs. Disadvantages of adhesive attachmentinclude that both the fixture or bracket and the attachment surface mayrequire pre-treatment, like roughening and/or degreasing, and that anadhesive application operation is needed, then followed by operations toposition and mount the fixture or bracket under application of pressure.These steps again involve process costs. Significant advances havealready been made in these respects by the present applicant, asdescribed in published European patent application EP 2 813 432 A1.

SUMMARY

In several aspects, the present disclosure provides a new, improved andoptimised method or technique in that regard. In particular, it would beuseful to provide a new method of installing a fixture or bracket in oron a structure of an aircraft or spacecraft, so that a faster or moreeconomical procedure may be realized.

It would thus be useful to provide a new and improved method ofinstalling a fixture or bracket in or on a structure of an aircraft orspacecraft which improves production efficiency and work-flows. It wouldfurther be desirable to provide a new and improved apparatus forinstalling such a fixture or bracket in or on a structure of an aircraftor spacecraft.

According to one aspect, therefore, the disclosure herein provides amethod of installing a fixture, such as a bracket, in or on a structureof a vehicle, such as a body or fuselage structure of an aircraft orspacecraft, comprising the steps of:

arranging an apparatus in, on or adjacent the structure;

pre-treating a surface region of the structure by heat ablation usingthe apparatus; and

forming the fixture in situ on the structure at the pre-treated surfaceregion based upon a digital model of the fixture using the apparatus,wherein the fixture is installed by connecting the fixture to thestructure at the pre-treated surface region as the fixture is formed.

In this way, the installation of the fixture, including pre-treatment ofthe surface region of the structure at which the fixture is installed,may essentially occur automatically via the apparatus arranged in, on oradjacent to that structure. Thus, the method provides maximumflexibility in the fuselage assembly procedure and does not requireseparate or external manufacture of individual fixtures or brackets.Pre-treating the surface region of the structure by heat ablation isable to remove any residues or impurities on the surface that mayotherwise interfere with or compromise the connection of the fixture tothe structure as it is formed. For example, if the structure comprisesfiber-reinforced polymer composite, such as CFRP, the ablation mayeffectively remove any residues of peel-plies, release films or mouldrelease agents. Also, pre-treating via ablation may somewhat roughen thesurface region for improved or enhanced connection of the fixturethereto.

There is also no need for any inventory of spare parts, as the fixturesare created directly from the digital model during installation.Similarly, there is no need for non-flying parts, e.g., which may berequired to fix a bracket on the structure during a curing process butwhich are then later removed. Further, the design of the fixtureencompasses a range of variants and can be readily adapted as designparameters change.

In a preferred embodiment, the step of forming the fixture in situ onthe structure includes providing or creating a three-dimensional digitalmodel of the fixture; arranging a head of an additive manufacturingapparatus in, on or adjacent the structure; and forming the fixture insitu on the structure with or via the head of the additive manufacturingapparatus based upon the digital model of the fixture.

In some embodiments, the step of forming the fixture in situ in or onthe structure comprises building the fixture by sequentially generatingand/or by building up layers of the fixture via the head of the additivemanufacturing device. In this regard, the layers of the fixture may besequentially deposited on the structure, such that the fixture is ableto be built up from these layers to its final three-dimensional formbased on the digital model. Accordingly, in some embodiments, the stepof connecting the fixture to the body or structure comprises one or moreof the layers of the fixture being bonded or fused to the fuselagestructure as it or they are generated and/or deposited on the vehiclestructure. Alternatively, or in addition, the one or more layers of thefixture may be bonded or fused to the fuselage structure in a curingstep that follows after the layers have been generated and/or depositedon the vehicle structure.

In some embodiments, the step of bonding of the fixture to the structureincludes depositing one or more layers or regions of adhesive on thestructure to which the fixture is to be connected. The depositing of thelayer(s) or region(s) of adhesive preferably occurs before generatingand building up layers of the fixture on the structure.

In some embodiments, the step of connecting the fixture to the structuremay include forming the fixture in a mechanical fit or a mechanicalengagement or connection with part of the structure. Indeed, the step ofconnecting the fixture to the structure may also comprise a combinationof bonding or fusing, together with a mechanical engagement orconnection.

In some embodiments, the digital model of the fixture includes data onan intended position of the fixture within structure, and the step ofpre-treating the surface region of the structure includes positioning ahead of the ablation device adjacent the structure based on the digitalmodel of the fixture. In this regard, the structure may optionallyinclude one or more reference markers for spatial correlation toreference points in the digital model of the fixture. One or moresensors may be provided for detecting and identifying the referencemarkers and then positioning the head of the ablation device based uponthe reference markers detected and identified.

In some embodiments, pre-treating the surface region of the structure byablation comprises laser ablating the surface region via a laserablation device. Thus, the step of laser ablating the surface regionpreferably includes one or more of: generating a laser beam; positioninga head of the laser ablation device at a predetermined spacing from thestructure; focusing the laser beam onto the surface region of thestructure; and/or moving the laser beam over the surface region at apredetermined spacing from the structure. The processing time for thesurface pre-treatment will typically be dependent on the thickness andamount of contamination on the surface. The intensity of the laser, andthus strength of the surface treatment is adjusted via the focal lengthof the laser. Accordingly, if the focal length is short, the laserintensity is increased, and if the focal length is long, the laserintensity is reduced.

In some embodiments, pre-treating the surface region of the structureincludes plasma ablating the surface region via a plasma ablationdevice. Thus, the step of plasma ablating the surface region comprisesone or more of: generating a plasma stream; positioning a head of aplasma ablation device at a predetermined spacing from the structure;focusing the plasma stream onto the surface region of the structure; andmoving the plasma stream over the surface region at a desired orpredetermined spacing from the structure. Again, process time of thepre-treating step will depend on a thickness and amount ofcontamination, and the strength or intensity of the plasma ablation maybe adjusted accordingly. But in general, the potential for contaminationremoval with plasma ablation is typically lower than with laserablation, so that a longer process time is usually required. The plasmaablation method has the advantage, however, that it is better suited touse with a structure having a more complicated shaped surface region. Inparticular, the plasma method is highly suited to surface regions ofcomplex geometry or curvature. Generally, also, the control of thespacing or gap in an airflow coupled plasma or gas plasma pre-treatmentis low compared with the laser ablation method. In other words, withplasma ablation, the surface pre-treatment does not need such preciseposition control.

In some embodiments, the method is designed or adapted for use with astructure comprised of a composite material, especially of afiber-reinforced polymer composite, such as a glass fiber-reinforcedpolymer (GFRP) composite or a carbon fiber-reinforced polymer (CFRP)composite. Thus, the additive manufacturing device may be configured togenerate or form the fixture from a material that is adapted to fuse orbond with a fiber-reinforced polymer in the structure. It will beappreciated, however, that the method may also be carried out with abody structure comprised of a metal, as is typical in conventionalairframes and fuselage structures, such that the additive manufacturingdevice is configured to generate or form the fixture from a materialthat can fuse or bond with the metallic structure. In addition to thefused or bonded connection that arises via this method, the fixture mayalso be secured with supplementary mechanical fasteners, such as rivets,screws, bolts or the like; such additional fasteners can be used toaugment a connection of the fixture to the vehicle structure.

In some embodiments, the step of forming or building the fixture withthe additive manufacturing device comprises any one or more of: fuseddeposition modelling (FDM), laser sintering (LS), selective heatsintering (SHS), and stereo-lithography (SLA). These techniques may begenerally referred to as three-dimensional (3D) printing. In the case ofstereo-lithography (SLA), the fixture will then typically be formed froma photo-polymer material, such as a UV-curable or UV-sensitive polymer.In the case of a fused deposition modelling (FDM) procedure, the fixturemay be formed from a curable polymer or thermoplastic polymer, such asacrylonitrile butadiene styrene (ABS) or a high-density poly-ethylene(HDPE), or from a metal, like a eutectic metal. In the case of selectiveheat sintering (SHS) or laser sintering (LS), the fixture may be formedfrom near any metal alloy, which is typically provided in a powdered orgranular form, but also from a range of polymers that may also be in apowdered or granular form. Examples of polymers that would be suitablefor series production of fixtures with a method of the presentdisclosure include DSM Somos® products NanoTool™, NanoForm™, andProtoTherm™. These polymers are UV-curable, such that they may behardened by irradiation with UV-light after their deposition in a finalshape of the fixture. In this regard, these DSM Somos® polymerstypically have a bending stiffness in the range of 79 to 121 N/mm² andtension stiffness in the range of 62 to 78 N/mm² after UV-hardening.Other suitable polymers include aliphatic or semi-aromatic polyamides,such as Nylon (Toray SQ133).

In some embodiments, the three-dimensional digital model of the fixtureincludes data on a specific or desired position of the fixture within oron structure. Thus, the step of forming the fixture in situ preferablyincludes positioning the head of the additive manufacturing devicewithin or on the structure based upon the data concerning the specificor desired position in the digital model. To this end, the body orfuselage structure may include one or more reference markers forproviding a spatial correlation to reference points in the digital modelof the fixture. One or more sensors may be provided for detecting andidentifying the reference markers and then positioning the head of theadditive manufacturing device based upon the detected and identifiedreference markers.

The positioning and movement of both the ablation device and theadditive manufacturing device may for example be computer-controlled.For example, the ablation device and the additive manufacturing device,or at least a respective head thereof, may be provided on a roboticassembly or a robotic arm, which is controllable to move and positionthe head of the device based upon the 3D digital model of the fixture.In this way, a very precise pre-treatment of the surface region and avery precise positioning of a fixture or bracket in or on the body orfuselage structure can be achieved, and with a high level ofrepeatability.

Although the method of the disclosure herein has been described abovewith specific reference to a vehicle, such as an aircraft or spacecraft,it will be appreciated by persons skilled in the art that the disclosureherein is also applicable to non-vehicular structures. For example, thedisclosure herein also provides a method of installing a fixture, suchas a bracket, on a stationary structure, such as a mast or tower for awind turbine or for an antenna (e.g., communication or TV antenna), abuilding, or other such structure. Furthermore, although the fixture maybe installed with the inventive method during fabrication of thestructure itself, it may also be subsequently installed in situ, e.g.,via a climbing or crawling robot assembly in the case of a mast, tower,building, or space station.

By employing the above method in space via a robot assembly thatincorporates the additive manufacturing device or 3D printer, e.g., tocarry out a repair or an installation job on a hull or outside of anorbiting space station, an astronaut can be spared the necessity of aspace-walk and associated risk. In other words, the fixture may beinstalled with the inventive method via a robot, which may operateunimpeded and substantially without risk in the environment of space.Thus, a movable robotic device, such as a climbing or crawling robot,can be used to perform the method of the disclosure herein.

In some embodiments, the digital model for the fixture may be createdand/or modified during the installation procedure. Where the method isbeing carried out, for example, to conduct a repair of part of thestructure, it may first be necessary to inspect and/or assess the partto be repaired before the precise shape and/or size of the fixturerequired can be ascertained. To this end, the method of the disclosureherein may include the step of examining a part of the structure toassess and/or determine the geometry and/or the dimensions of thefixture required, then providing or creating the three-dimensional (3D)digital model of the fixture based on the results of that examination.The robot assembly may therefore include examination equipment, such asa camera and/or one or more sensors to inspect and/or examine the partof the structure of interest.

An extension of the above concept includes the possibility of theadditive manufacturing device or 3D printer, e.g., set or provided on arobot, also generating or forming structural fixtures or elements forinstallation on the structure (e.g., on a hull of a space station). Suchfixtures or elements may also be provided in the form of tracks orrails, which may then influence or determine the movement or progress ofthe robot itself. These elements can, for example, be designed to chartor define a path of the robot to a specific location at which a repairmay need to be undertaken.

In the context of this description of the disclosure herein, it is to beappreciated that the step of “forming” the fixture or any portionthereof may be understood in the sense of producing or fabricating thatfixture or the portion thereof.

According to another aspect, the present disclosure provides anapparatus for installing a fixture, such as a bracket, in or on astructure of an aircraft or spacecraft, the apparatus comprising:

an ablation device configured to generate and direct an ablating beam orstream onto a surface region of a structure for pre-treating the surfaceregion;

an additive manufacturing device for forming the fixture in situ on thepre-treated surface region; and

a controller for controlling or operating the ablation device and/or theadditive manufacturing device adjacent or at the surface region of thestructure.

In some embodiments, the ablation device comprises a laser ablationdevice configured to generate and direct a laser beam onto the structurefor laser ablating the surface region. The laser ablation devicetypically includes a head having one or more of: a laser focusing deviceto adjust a focal length of the laser beam, and at least one sensor fordetecting a spacing or displacement of the head with respect to thesurface region of the structure. This way, the laser ablation device maybe configured to adjust the intensity of the heat ablation in dependenceupon the degree of residues or impurities present and the material ofthe structure.

In some embodiments, the laser ablation device includes a laser headhaving a laser power in the range of 10 to 50 W (e.g., 20 W) and awavelength of 1000 nm. The focusing device may comprise a convergencelens for laser beam. A convergence lens may be dependent on the spacingor distance from laser head to the target surface region. A variablefocus lens will be suitable for laser surface treatment. A CL20 backpackis an example of a laser generator suitable as a hand held laser surfacetreatment system for this apparatus.

In some embodiments, the ablation device comprises a plasma ablationdevice configured to generate and direct a plasma stream onto thestructure for plasma ablating the surface region. Surface contaminationsare evaporated by heat of the plasma. And, the fiber-reinforced polymer(FRP) surface is roughed by the plasma at the same time of removing ofcontamination. The plasma ablation device will typically include a headhaving one or more of: a focusing device to direct or focus the plasmastream, and at least one sensor for detecting a spacing or displacementof the head with respect to the surface region. Again, the ablationdevice may thereby be configured to adjust the intensity of the plasmaablation depending upon the degree of residues or impurities present andthe material of the structure.

In some embodiments, the plasma ablation device may include a plasmahead provides as an airflow-coupled plasma head or a gas plasma head.The plasma ablation device may operate at a power in the range of 200 to1000 W (e.g., 600 W derived from 10 kV, 60 mA AC).

In some embodiments, the additive manufacturing device comprises a headfor building the fixture sequentially, especially by generating andbuilding up layers of the fixture on the structure, wherein the layersof the fixture are sequentially deposited on the structure by the head.The head of the additive manufacturing device preferably includes anozzle portion configured for dispensing and/or applying a bondingadhesive, especially in layers or filaments, to the structure. Further,the nozzle portion may also configured for dispensing and/or applyingone or more layers of filling material for generating and building uplayers or filaments of the fixture on the structure.

As noted above, each head of the apparatus desirably includes at leastone distance sensor, and more preferably a plurality of distance sensorsand/or contact sensors, for measuring or sensing a position or spacingof the head with respect to the surface region of the structure on whichthe fixture is to be formed. A high level positioning accuracy isimportant both for the ablation device for surface pre-treatment and forthe additive manufacturing device (i.e., 3D printer) for fineness oflayer pitch. This means not only robot arm positioning, but alsorelative accuracy of the head with respect to the structure (e.g.,fuselage).

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and theadvantages thereof, exemplary embodiments of the disclosure herein areexplained in more detail in the following description with reference tothe accompanying drawings, in which like reference characters designatelike parts and in which:

FIG. 1 is a schematic side view of a section of a fuselage or hullstructure of an aircraft, upon which a fixture or bracket is beinginstalled according to an embodiment of the disclosure herein;

FIG. 2 shows four schematic side views (a) to (d) of the fuselage orhull structure in FIG. 1, upon which the fixture or bracket is beinginstalled according to an embodiment of the disclosure herein;

FIG. 3 is a schematic side view of a section of a fuselage or hullstructure of an aircraft, and an apparatus according to an embodiment ofthe disclosure herein with which a fixture or bracket is installed insitu;

FIG. 4 is a schematic side view of the apparatus according to theembodiment of FIG. 3 showing the parts of the apparatus for performing apre-treatment of a surface region of the structure in more detail;

FIG. 5 is a schematic side view of a section of a fuselage or hullstructure of an aircraft, and an apparatus according to anotherembodiment of the disclosure herein for installing a fixture or bracketin situ;

FIG. 6 is a schematic side view of the apparatus according to theembodiment of FIG. 5 showing the parts of the apparatus for performing apre-treatment of a surface region of the structure in more detail;

FIG. 7 schematically shows three stages (i) to (iii) of a method ortechnique of installing the fixture or bracket according to a particularembodiment;

FIG. 8 is a flow diagram which schematically illustrates a methodaccording to a preferred embodiment;

FIG. 9 is a schematic illustration of an aircraft in which one or morebrackets according to an embodiment of the disclosure herein areinstalled; and

FIG. 10 is a schematic view of a space station upon which a fixture orelement is being installed according to an embodiment of the disclosureherein.

DETAILED DESCRIPTION

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure and are incorporated in andconstitute a part of this specification. The drawings illustrateparticular embodiments of the disclosure herein and together with thedescription serve to explain the principles of the disclosure herein.Other embodiments of the disclosure herein and many of the attendantadvantages of the disclosure herein will be readily appreciated as theybecome better understood with reference to the following detaileddescription.

It will be appreciated that common and well understood elements that maybe useful or necessary in a commercially feasible embodiment are notnecessarily depicted in order to facilitate a more abstracted view ofthe embodiments. The elements of the drawings are not necessarilyillustrated to scale relative to each other. It will further beappreciated that certain actions and/or steps in an embodiment of amethod may be described or depicted in a particular order of occurrenceswhile those skilled in the art will understand that such specificitywith respect to sequence is not necessarily required. It will also beunderstood that the terms and expressions used in the presentspecification have the ordinary meaning as is accorded to such terms andexpressions with respect to their corresponding respective areas ofinquiry and study, except where specific meanings have otherwise beenset forth herein.

With reference firstly to FIG. 1 of the drawings, a system or apparatus100 for installing a fixture 1, here in the form of a bracket, on anairframe or fuselage structure F of an air-craft according to a methodof the disclosure herein is illustrated schematically. The airframe orfuselage structure F of the aircraft in this embodiment comprises acurved shell section of the fuselage, comprised of a carbon-fiberreinforced polymer composite, which is supported in this case by braceelements B extending horizontally from a vertically extending supportingframework S. Also shown in FIG. 1 is a robot assembly 2, which includesa robotic arm 3 having a plurality of articulated joints 4, each ofwhich is drivable in at least one and preferably in a number ofdegrees-of-freedom. The robot assembly 2 is itself mounted fortranslational movement along a rail member 5 in a directionperpendicular to a plane of drawing FIG. 1.

Mounted on a distal end region of the robot arm 3 is a head 6 of anadditive manufacturing device 7, which is generally understood or may bereferred to as a 3D printer device. This additive manufacturing device 7may operate on any one of the known 3D printing techniques, such asfused deposition modelling (FDM), laser sintering (LS), orstereo-lithography (SLA). Particularly preferred in this embodiment is afused deposition modelling (FDM) device 7. The movement of the roboticassembly 2, and more particularly of the robot arm 3 via the articulatedjoints 4 and its position along the rail member 5, arecomputer-controlled via a computer processor P (illustratedschematically here, and shown later in FIG. 7), which also controlsoperation of the additive manufacturing device 7. During installation ofa new fixture or bracket 1 according to the inventive method, the head 6of the device 7 is moved by the robot arm 3 in the direction of thearrow in FIG. 1 to a predetermined position or surface region Z on thefuselage shell F.

Referring now also to FIGS. 2(a) to 2(d) of the drawings, the steps offorming or building the fixture or bracket 1 in the surface region Z ofthe fuselage structure F is illustrated schematically in the series offour images (a) to (d). In the image of FIG. 2(a), the head 6 of the FDMdevice 7 arranged at the distal end region of the robotic arm 3 has beenmoved into proximity with the surface of the fuselage structure F of theaircraft at position Z. A three-dimensional digital model M of thefixture or bracket 1 is provided or generated in the computer processorP and, based upon the data in this digital model M of the bracket 1, thecomputer processor P then controls the head 6 of the FDM device 7 todeposit layers of polymer material onto the CFRP fuselage structure asthe head 6 of the device 7 is moved along the surface of shell structureF in the direction of the arrow in FIG. 2(a). Then, in FIG. 2(b), one ormore layers L1 of the bracket 1 has/have been deposited upon thefuselage structure F at the predetermined position Z, which layer(s)is/are bonded or fused to CFRP structure F.

The head 6 of the FDM device 7 is then moved slightly away from thefuselage structure F in the direction of the arrow shown in FIG. 2(b).As shown in FIG. 2(c), the head 6 may then commence deposition of one ormore new layers L2 of the polymer material, which builds upon theprevious layers L1 and thus builds-up the three-dimensional shape orform of the fixture or bracket 1. This procedure continues withreference to FIG. 2(d) of the drawings until the final 3D shape of thebracket 1 has been completed.

Before the controller or processor P commences operating the ALM oradditive manufacturing device 7 mounted on the robotic assembly 2,however, the apparatus 100 is used or employed to pre-treat the surfaceregion Z at which the bracket 1 is to be installed on the structure F byheat ablation. To this end, as illustrated in FIGS. 3 and 4 of thedrawings, the apparatus 100 further includes an ablation device 9, ahead 8 of which is mounted on a distal end region of a robot arm 3 inthe robotic assembly 2. As noted above, movement of the robotic assembly2, and specifically of the robot arm 3 via the articulated joints 4, iscontrolled via the processor P.

Referring to FIG. 3, in this embodiment the ablation device 9 is a laserablation device configured to generate and direct a laser beam LB ontothe fuselage structure F for laser ablating the targeted surface regionZ. The ablation device 9 includes a laser generator 10 in the form of aCL20 backpack which is supported on a carriage robot 11 and connectedwith the laser ablation head 8 via an optical cable 12, e.g., of opticalfibers, for transmitting the laser beam LB. The laser generator 10 israted at 20 W, generates a laser beam LB with a wavelength of 1000 nm,and is powered by a portable battery pack 13, which is movably supportedon a carriage robot 14 within the apparatus 100.

As represented only very schematically in drawing FIG. 4, the laserablation head 8 includes a focusing lens 15, a focusing control unit 16and a battery unit 17, which together operate to adjust a focal lengthof the laser beam LB emitted from the head 8. In this way, the focusinglens 15 and focusing control unit 16 cooperate to adjust an intensity ofthe laser ablation. Further, the head 8 of the laser ablation device 9includes a position sensor unit 18 for detecting a spacing or gap δ(and, thus, also a displacement or change in position) of the head 8with respect to the surface region Z being pre-treated by laserablation. This spacing or gap δ, which will generally correspond to thefocal length adjusted via lens 15 and control unit 16, is typicallywithin the range of about 50 mm to about 100 mm. Furthermore, with laserablating, the spacing or gap δ is typically controlled and maintainedvery precisely.

With reference now to FIGS. 5 and 6 of the drawings, it will be notedthat, in another embodiment of the apparatus 100, the ablation device 9is a plasma ablation device configured to generate and direct a plasmastream PS onto the fuselage structure F for plasma ablating the desiredsurface region Z. The plasma ablation device 9 comprises a generatorcontrol unit 19 which is supported on a movable carriage robot 20 andconnected via a power cable 21 both with a battery pack 22 (also on acarriage robot 20) and with the plasma head 8. The plasma ablationdevice 9 in this case operates at 600 W on AC having 10 kV and 60 mA.

The plasma stream PS itself is generated at the head 8, which is an airflow coupled plasma head 8. As is represented only very schematically indrawing FIG. 6, the ablation head 8 in this case includes a positionsensor unit 23, a gap control unit 24, and a ball screw and motor 25,which co-operate to monitor and adjust the spacing or gap δ (and, thus,also a displacement or change in position) of the ablation head 8 withrespect to the surface region Z being pre-treated. This spacing or gap δis typically within the range of about 10 mm to about 30 mm, but highprecision is generally not required.

Fourier transform infrared spectroscopy (FTIR) NDI equipment may beemployed to check the degree of residue removal and/or heat damage bythe heat ablation pre-treatment. If a long time has elapsed since heatablation pre-treating a surface region, a re-treatment of the surfacemay be conducted to ensure or maintain the good surface condition by thepre-treatment process. Such a re-treatment process will generally be thesame as described above, but the power or intensity may be lower in viewof the low amount of material to remove.

With reference also now to FIG. 7 of the drawings, the method accordingto this preferred embodiment of the disclosure herein is illustrated inthe three stages (i) to (iii). For example, in FIG. 7(i) an operator Ois shown at a work-station W of the computer processor P engaged in thetask of providing and/or generating the three-dimensional (3D) digitalmodel M of the fixture or bracket 1 to be installed according to themethod of this embodiment. The computer processor P at which theoperator O is working is also responsible for the computer-controlledoperation of the robot assembly 2, as well as both the additivemanufacturing device 7 and the ablation device 9 described above withrespect to FIGS. 1 to 6.

FIG. 7(ii) schematically illustrates the step of positioning the robotassembly 2 with respect to the fuselage structure F upon which thebracket 1 is to be formed and installed. In this regard, the robotassembly 2 is movable on one or more rails 5 within the tubular fuselagestructure F, preferably on one of a plurality of separate rails 5, e.g.,at separate heights or separate floors in the fuselage F. In thisregard, the fuselage structure F may be a tubular shell as seen in FIG.7(ii), rather than just a shell section shown in FIG. 1. Also, the robotassembly 2 may include a plurality of robotic arms 3 for simultaneouslyoperating at various different positions Z within the fuselage structureF, i.e., in order to simultaneously pre-treat the respective surfaceregions and to build and install a plurality of fixtures or brackets 1at different positions Z.

With regard to the positioning of the robotic assembly 2, the digitalmodel M of the fixture or bracket 1 may include data concerning aspecific desired or predetermined surface region or position Z on thefuselage structure F for a particular bracket 1. This data can then beused together with reference markers R provided on the fuselagestructure F, which are preferably detectable and identifiable by sensors(not shown) provided on the robot assembly 2 to give spatial correlationfor moving the robotic arm 3 relative to the body or fuselage structureF, and especially the head 9 of an ablation device 8 and the head 6 ofan additive manufacturing device 7, to the correct position or surfaceregion Z for pre-treating the surface and then forming and installing aspecific bracket 1 based upon the data in the digital model M. The datain the digital model may also include detailed data on the structure Fin or on which the bracket or fixture 1 is to be installed.

In other words, FIG. 7(ii) represents controlling operation of both theablation device 9 and the additive manufacturing device 7 in theapparatus 100 for performing both the steps of: pre-treating the surfaceregion Z of the structure F by heat ablation using the ablation device 9provided on the robotic assembly 2, and then forming the bracket orfixture 1 in situ on the structure at the pre-treated surface region Zusing the ALM device 7 on the robotic assembly 2.

FIG. 7(iii) essentially corresponds to FIG. 2 of the drawings andschematically illustrates the sequential deposition or layer build-upand installation of a particular bracket 1 at the desired orpredetermined position Z within the fuselage structure F, with thebracket 1 being simultaneously bonded or fused to the material of thefuselage structure F.

Referring now to FIG. 8 of the drawings, a flow diagram is shown thatagain schematically illustrates the steps in the method of the preferredembodiment. In this regard, the first box I of FIG. 8 represents thestep of arranging an apparatus 100 in, on or adjacent to the structureF, as generally shown in FIGS. 1, 3 and 5 of the drawings. The secondbox II then represents the step of pre-treating a surface region Z ofthe structure F by heat ablation using the laser/plasma ablation device9 on the apparatus 100 to remove contaminant residues from the surfaceregion Z and thereby to prepare the surface region Z for connection ofthe bracket or fixture 1. In this regard, this step involves controllingmovement of the head 8 of the ablation device 9 with respect to thepredetermined position Z in the fuselage structure F based on positiondata in the digital model M of the bracket or fixture 1 via theprocessor or control unit P. The third box III represents the step ofdepositing one or more layer or region of adhesive on the pre-treatedsurface region Z for subsequently bonding the bracket or fixture 1 tothe CFRP fuselage structure F. The final box IV in drawing FIG. 8represents the step of forming the bracket 1 in situ on the fuselagestructure F with the head 6 of the FDM device 7. This involves movingthe head 6 of the FDM device 7 to the pre-treated surface region Z inthe fuselage structure F based on position data in the three-dimensionaldigital model M and then sequentially building up the bracket 1 inlayers L1, L2 based upon the digital model M in the computer processorP, which operates and controls the robot assembly 2 carrying the FDMdevice 7. The bracket 1 is connected by bonding to the CFRP fuselagestructure F as the bracket 1 is formed.

Following the above description of the method and apparatus of thedisclosure herein, FIG. 9 of the drawings now schematically illustratesan aircraft A that incorporates a fuselage structure F, in which atleast one fixture or bracket 1, and preferably a plurality thereof, hasor have been installed according to a method of the present disclosure.

With reference to FIG. 10 of the drawings, on the other hand, analternative embodiment is now illustrated schematically. In thisembodiment, the inventive method is being carried out on a space stationT which is currently in orbit. The space station T includes solarcollector modules C, modules H for human occupation, and an antennamodule I, all of which are interconnected by a structural framework X.In this example, the method is employed to conduct a repair to a part onthe antenna module I. Again, a robot assembly 2, which includes arobotic arm 3 having remotely controlled articulated joints 4 isemployed, which avoids the need for an astronaut to under-take aspace-walk. The structural framework X may include one or more rails 5for guiding movement of the robot 2 to the antenna module I. Also, ahead 6 of an additive manufacturing device 7 or 3D printer device ismounted at an end region of the robotic arm 3. In this way, the methoddescribed above with reference to FIGS. 1-8 can be performed with therobot assembly 2 on the space station T to generate and install a newelement or fixture 1 to repair the antenna module I. In the event thatno rails 5 are available for the robot 2 on the structural framework X,it will be noted that the head 6 of the additive manufacturing device 7may also be used to generate and install rail members 5 on the frameworkX of the space station T according to the method of the disclosureherein for guiding the robotic assembly 2 to that part of the antennamodule I to be repaired.

Although specific embodiments of the disclosure herein have beenillustrated and described herein, it will be appreciated by those ofordinary skill in the art that a variety of alternate and/or equivalentimplementations exist. It should be appreciated that the exemplaryembodiment or exemplary embodiments are only examples, and are notintended to limit the scope, applicability, or configuration in any way.Rather, the foregoing summary and detailed description will providethose skilled in the art with a convenient road map for implementing atleast one exemplary embodiment, it being understood that various changesmay be made in the function and arrangement of elements described in anexemplary embodiment without departing from the scope as set forth inthe appended claims and their legal equivalents. Generally, thisapplication is intended to cover any adaptations or variations of thespecific embodiments discussed herein.

In this document, the terms “comprise”, “comprising”, “include”,“including”, “contain”, “containing”, “have”, “having”, and anyvariations thereof, are intended to be understood in an inclusive (i.e.,non-exclusive) sense, such that the process, method, device, apparatusor system described herein is not limited to those features or parts orelements or steps recited but may include other elements, features,parts or steps not expressly listed or inherent to such process, method,article, or apparatus. Furthermore, the terms “a” and “an” used hereinare intended to be understood as meaning one or more unless explicitlystated otherwise. Moreover, the terms “first”, “second”, “third”, etc.are used merely as labels, and are not intended to impose numericalrequirements on or to establish a certain ranking of importance of theirobjects.

While at least one exemplary embodiment of the present invention(s) isdisclosed herein, it should be understood that modifications,substitutions and alternatives may be apparent to one of ordinary skillin the art and can be made without departing from the scope of thisdisclosure. This disclosure is intended to cover any adaptations orvariations of the exemplary embodiment(s). Furthermore, characteristicsor steps which have been described may also be used in combination withother characteristics or steps and in any order unless the disclosure orcontext suggests otherwise. This disclosure hereby incorporates byreference the complete disclosure of any patent or application fromwhich it claims benefit or priority.

What is claimed is:
 1. A method of installing a mounting fixture in oron a structure of an aircraft or spacecraft, the method comprising:arranging an apparatus in, on or adjacent the structure; pre-treating asurface region of the structure by ablation using the apparatus; andforming the mounting fixture in situ on the structure at the pre-treatedsurface region using the apparatus based on a digital model of themounting fixture, wherein the mounting fixture is installed byconnecting the mounting fixture to the structure at the pre-treatedsurface region as the mounting fixture is formed.
 2. The method of claim1, wherein pre-treating the surface region of the structure by ablationcomprises laser ablating the surface region via a laser ablation device.3. The method of claim 2, wherein laser ablating the surface regioncomprises one or more of: generating a laser beam; positioning a head ofthe laser ablation device at a predetermined spacing from the structure;focusing the laser beam onto the surface region of the structure; andmoving the laser beam over the surface region at a predetermined spacingfrom the structure.
 4. The method of claim 1, wherein pre-treating thesurface region of the structure by ablation comprises plasma ablatingthe surface region via a plasma ablation device.
 5. The method of claim4, wherein plasma ablating the surface region comprises one or more of:generating a plasma stream; positioning a head of a plasma ablationdevice at a predetermined spacing from the structure; focusing theplasma stream onto the surface region of the structure; and moving theplasma stream over the surface region at a predetermined spacing fromthe structure.
 6. The method of claim 1, wherein the digital model ofthe mounting fixture includes data on an intended position of themounting fixture within structure, wherein pre-treating the surfaceregion of the structure includes positioning a head of the ablationdevice adjacent the structure based on the digital model of the mountingfixture, whereby the structure can include one or more reference markersfor spatial correlation to reference points in the digital model of themounting fixture.
 7. The method of claim 1, wherein forming the mountingfixture in situ comprises building the mounting fixture sequentially,preferably by generating and building up layers of the mounting fixturein the surface region with an additive manufacturing device, wherein thelayers of the mounting fixture are sequentially deposited on thestructure.
 8. The method of claim 1, wherein connecting the mountingfixture to the structure includes at least one of: bonding or fusing oneor more of the layers of the mounting fixture to the structure as theyare generated; and forming the mounting fixture in situ in a mechanicalfit or a mechanical engagement with part of the structure.
 9. The methodof claim 8, wherein bonding the mounting fixture to the structureincludes depositing one or more layer or region of adhesive on thepre-treated surface region.
 10. An apparatus for installing a mountingfixture in or on a structure of an aircraft or spacecraft, the apparatuscomprising: a robot assembly movable with respect to the structure; anablation device mounted on the robot assembly, the ablation device beingconfigured for generating and directing an ablating beam onto a surfaceregion of the structure to pre-treat the surface region; an additivemanufacturing device mounted on the robot assembly, the additivemanufacturing device being configured for forming the mounting fixturein situ on the pre-treated surface region; and a controller forcontrolling or operating the ablation device and/or the additivemanufacturing device at the surface region of the structure.
 11. Theapparatus of claim 10, wherein the ablation device comprises a laserablation device for laser ablating the surface region, wherein the laserablation device includes a head having one or more of: laser focussingdevice to adjust a focal length of the laser beam, and at least onesensor for detecting a spacing or displacement of the head with respectto the surface region.
 12. The apparatus of claim 10, wherein theablation device comprises a plasma ablation device for plasma ablatingthe surface region, wherein the plasma ablation device includes a headhaving one or more of: laser focusing device to direct or focus a plasmastream, and at least one sensor for detecting a spacing or displacementof the head with respect to the surface region.
 13. The apparatus ofclaim 10, wherein the additive manufacturing device comprises a head forbuilding the mounting fixture sequentially, especially by generating andbuilding up layers of the mounting fixture on the structure, wherein thelayers of the mounting fixture are sequentially deposited on thestructure by the head.
 14. The apparatus of claim 10, wherein each ofthe additive manufacturing device and the ablation device are mounted onone of a plurality of robotic arms of the robot assembly for adjusting aposition thereof with respect to the structure.
 15. The apparatus ofclaim 10, wherein the controller operates or controls based on a digitalmodel of the mounting fixture or structure.
 16. The method of claim 9,wherein depositing one or more layer or region of adhesive on thepre-treated surface region is performed before generating and buildingup layers of the mounting fixture on the structure.